1. Field of the Invention
The present invention relates to an information processing apparatus. Specifically, the present invention relates to an information processing apparatus such as a cellular phone which can simultaneously display a plurality of windows by a multi-window system.
2. Description of the Related Art
In recent years, cellular phones as information processing apparatuses are increasingly equipped with not just a communication function via a telephone call but also such functions as an address book function, an e-mail function via a network such as a base station or the Internet, a browser function allowing browsing of Web pages or the like, and further a music control function allowing listening of audio data, and a function allowing reception of terrestrial digital one-segment broadcast waves. Also, it is becoming increasingly possible to reproduce received images based on terrestrial digital one-segment broadcast waves, or various video contents acquired by other means, on cellular phones.
Recently, cellular phones equipped with a multi-window system are also proposed. This multi-window system represents a method of implementing window applications by placing display parts on a plurality of windows. In cellular phones equipped with a multi-window system, a plurality of window applications run simultaneously on the screen, and a plurality of windows are displayed simultaneously.
Examples of application programs (window applications) using windows on the screen include application programs related to reproduction of moving images (that is, video reproduction application programs), and application programs related to transmitting/receiving and generation of e-mails. As an example of techniques related to reproduction of moving images, a technique is known in which if performing a decoding process on a moving image that places a high processing load, upon detecting that the processing load involved (for example, the processor usage, the memory usage, or the like) is high, part of the decoding process on the moving image is omitted (see, for example, Japanese Unexamined Patent Application Publication No. 2006-101405).
According to the technique disclosed in Japanese Unexamined Patent Application Publication No. 2006-101405, the video reproduction application program detects the current load on the computer, and if the current load on the computer is not high, the video reproduction application program executes a normal decoding process in which all encoded screens are decoded, and if the current load on the computer becomes high, the video reproduction application program executes a decoding process that omits decoding of unreferenced screens which are not referenced from other screens. This allows decoding of a moving image to be executed smoothly.
Consider a case where, in the multi-window system in which a plurality of window applications run simultaneously on the screen, and a plurality of windows are displayed simultaneously, an application program that places a high load on the CPU, for example, an application program related to reproduction of moving images, exists among the window applications that are running. In this case, upon attempting to execute another application program simultaneously with processing by this application program related to reproduction of moving images, even if a command is input to the cellular phone when an input unit is operated by the user, it takes some time until the command is accepted by the other application, which not only detracts from the responsiveness of the cellular phone but also detracts from the ease of use for the user.
Of course, if the technique disclosed in Japanese Unexamined Patent Application Publication No. 2006-101405 is used, when the current load on the computer becomes high, a decoding process that omits decoding of unreferenced screens which are not referenced from other screens can be executed, and this would make it possible to execute decoding of a moving image smoothly. However, since part of the decoding process on a moving image is omitted in all cases regardless of whether the user is looking at the moving image or not, even when the user is looking at the moving image, part of the decoding process on the moving image is omitted against the user's will, resulting in loss of smoothness of motion upon reproducing the moving image.